The present invention relates to electric motors in general, especially to explosion-proof canned electric motors which are operated at elevated temperatures, and more particularly to improvements in means for counteracting the adverse influence of condensate and/or other liquids in the housings of such motors.
Explosion-proof electric motors are often of the type d (denoting pressure-tight) wherein condensate tends to accumulate as a result of changes in ambient temperature. In a simple electric motor, the condensate is evacuated through a bore, port or an analogous opening in the motor housing. In presently known explosion-proof electric motors, condensate which accumulates in the housing is collected in a bag or a similar receptacle whose contents can be evacuated from time to time by removing a liquid-discharging screw or by rotating and/or axially displacing a suitable piston.
The just described mode of accumulating and removing condensate is not satisfactory in electric motors which are operated at elevated temperatures and contain ceramic insulating materials. Moist air/or condensate in the interior of the housing affects the insulating qualities of ceramic materials, often to such an extent that the motor is brought to a stop or damaged.